fix: stabilize learning path, reliability and legacy Windows builds

Unify beginner syntax while preserving compatibility, repair ownership and parser guards, add verified distribution tooling and VC6 Windows 98 build inputs, and clarify documentation and release status. Preserve DOS build-input line endings and exclude generated binaries/caches.

tools/validate_learning_ownership.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+"""Run the full introductory learning path with invalid-access and leak checks."""
+from pathlib import Path
+import os
+import subprocess
+import sys
+import tempfile
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def main():
+    if os.name == 'nt':
+        print('SKIP: learning LeakSanitizer validation requires POSIX')
+        return
+    with tempfile.TemporaryDirectory(prefix='claro-learning-ownership-', dir=os.environ.get('TMPDIR')) as tmp:
+        binary = Path(tmp) / 'claro-asan'
+        subprocess.run(['gcc', '-std=c89', '-pedantic-errors', '-Werror=implicit-function-declaration', '-O0', '-g', '-fsanitize=address,undefined', str(ROOT / 'src/claro.c'), '-o', str(binary), '-lm'], check=True)
+        env = dict(os.environ, ASAN_OPTIONS='detect_leaks=1:halt_on_error=1', UBSAN_OPTIONS='halt_on_error=1', CLARO_EXE=str(binary))
+        for checker in ['validate_learning_syntax.py', 'validate_first_hour.py']:
+            result = subprocess.run([sys.executable, str(ROOT / 'tools' / checker)], cwd=ROOT, env=env, capture_output=True, text=True, timeout=90)
+            if result.returncode:
+                print(result.stdout + result.stderr)
+                raise SystemExit(result.returncode)
+            print('PASS: leak-checked', checker)
+    print('PASS: introductory lessons, examples, checker paths and REPL under ASan/UBSan/LSan')
+
+
+if __name__ == '__main__':
+    main()